Fossil fuels are the primary source of energy for the planet. The rate of fossil fuel consumption is likely outpace the rate of fossil fuel production as the planet's population continues to grow and as less economically developed countries become industrialized. This expected increase in demand for fossil fuels could exhaust the global supplies of fossil fuels within the next several decades if consumption continues at the present rate.
It is desirable to harness energy from renewable sources such as solar power, wind power, hydro power, and/or geothermal power to minimize dependence on fossil fuels.